System Center Virtual Machine Manager (VMM) 2008 or VMM 2008 R2 can scale across a wide range of virtual environments from a stand-alone VMM implementation with all VMM components installed on a single computer, managing a virtual environment with up to 20 hosts, to a fully distributed enterprise environment, managing hundreds of hosts and thousands of virtual machines dispersed across a wide geographic area.

The modularity of the VMM components allows you to configure your VMM implementation in a manner that best meets the management needs and objectives of your virtual environment. You can install all VMM components on a single computer, install more than one VMM component on a single computer, or install each VMM component on a different computer, depending on the size and complexity of your environment.

If your environment has multiple data centers, you can choose to deploy a central VMM implementation to manage the virtual environments for all of your data centers, or deploy separate VMM implementations in each data center to manage its virtual environment. If your environment has a large development and testing environment, you can deploy a separate VMM implementation to exclusively manage that virtual environment. For more information, see Planning for the VMM Server (http://go.microsoft.com/fwlink/?LinkId=163030).

Supported Upgrade and Migration Paths

VMM 2008

You can migrate to VMM 2008 from the following previous versions of VMM:

VMM 2008 is also available in an evaluation version, which expires 180 days after installation, and in a Workgroup version, which is limited to managing five or less hosts. You can upgrade to VMM 2008 from either of these versions by uninstalling your present version of VMM, while retaining the VMM database, and then installing VMM 2008 using the retained database. For more information about uninstalling VMM, see Uninstalling VMM Components. For more information about reinstalling VMM with a retained database, see Reinstalling VMM with a Retained Database.

System Requirements

This section provides a brief overview of the system requirements for VMM and links to other sections of the documentation that provide more detailed information.

The hardware requirements for installing each VMM component vary and are presented as both the minimum and the recommended requirements. A critical factor for the successful operation of a VMM implementation is to correctly configure the hardware for all VMM components. This is especially true for virtual machine hosts. Just as with physical computers, the overall performance of a virtual machine depends significantly on the level of available resources on the virtual machine host.

The hardware and software requirements are provided for installing all VMM components on a single computer and for installing each VMM component on a separate computer. If you want to install more than one VMM component on a single computer, you should meet the highest hardware requirements for any one of the components that you want to install.

In a Windows Server 2003 domain, a Windows Server 2003 domain functional level is required. For information about features supported at the Windows Server 2003 functional level and guidance on raising the functional level, see Functional Levels Background Information (http://go.microsoft.com/fwlink/?LinkId=184527).

For information about domain configurations that are supported for managed virtual machine hosts, see Adding Hosts (http://go.microsoft.com/fwlink/?LinkId=121818).

Supported Number of Hosts and Virtual Machines

The maximum number of hosts and virtual machines tested with and supported by VMM on the highest recommended hardware configuration is 400 hosts and 8,000 virtual machines.

If your VMM implementation has over 150 hosts, we strongly recommend that you enable server-optimized garbage collector (GC) on the VMM server instead of the default workstation garbage collector. This can significantly reduce the CPU utilization on the VMM server and improve your performance for parallel VMM operations.

To enable server-optimized garbage collector (GC) on the VMM server, create a file that is named vmmservice.exe.config by using the following code, and then for VMM 2008, place it into the %SYSTEMDRIVE%\Program Files\Microsoft System Center Virtual Machine Manager 2008\Bin directory on the VMM server, or for VMM 2008 R2, place it into the %SYSTEMDRIVE%\Program Files\Microsoft System Center Virtual Machine Manager 2008 R2\Bin directory on the VMM server.

Windows Server 2008 R2 Hyper-V Host Management

With VMM 2008 R2, you can create and manage virtual machines that are running on Windows Server 2008 R2 Hyper-V hosts. When you add a host that is running Windows Server 2008 R2 and that does not have Hyper-V enabled, VMM 2008 R2 automatically enables the Hyper-V role on the host.

VMM 2008 R2 supports the following new features of Windows Server 2008 R2:

Live migration between Windows Server 2008 R2 clustered hosts. With live migration, you can migrate a virtual machine from one node of a Windows Server 2008 R2 failover cluster to another node in the same cluster without any downtime. Because the virtual machine does not experience any downtime, the move is completely transparent to the users who are connected to the virtual machine.

Network adapters that support the VMQ feature can create a unique network queue for each virtual network adapter and then connect that queue directly to the virtual machine’s memory. This connection routes packets directly from the hypervisor to the virtual machine, bypassing much of the processing in the virtualization stack.

Network adapters that support the TCP Chimney Offload feature can offload the processing of network traffic from the networking stack. Both features increase network performance and reduce CPU utilization.

Hot addition and removal of virtual hard disks (VHDs). In Windows Server 2008 R2, Hyper-V lets users add and remove VHDs from a virtual machine while it is running.

Support for Installing VMM Components on Virtual Machines

VMM supports the installation of VMM components on virtual machines. However, you cannot use a virtual machine as a host.

Importante

If you install the VMM server on a virtual machine, do not migrate this virtual machine to another host from within the VMM Administrator Console. If the virtual machine is highly available, do not migrate this virtual machine to another node on the cluster from within the VMM Administrator Console. When the VMM server is running on a virtual machine, it is literally managing itself; therefore any migration, including quick migration, will result in a service interruption.

Also, if you enable Performance and Resource Optimization (PRO) for the host group or host cluster that contains the virtual machine running the VMM server, exclude that virtual machine from PRO. This prevents PRO-initiated migration of the virtual machine if high CPU or memory usage on the host, or some other condition monitored by PRO, causes PRO to recommend migration of a virtual machine. For information about excluding a virtual machine from PRO-initiated migrations, see Creating New Virtual Machines (http://go.microsoft.com/fwlink/?LinkID=162793).

Support for Storage Area Networks

VMM supports the following SANs for the transfer of virtual machine files:

Fibre Channel

N_Port ID Virtualization (NPIV) Fibre Channel

iSCSI SANs using the Microsoft Initiator

VMM requires that you create a single volume on each disk. A virtual machine on a LUN that contains multiple volumes cannot be transferred on a SAN. For more information, see Configuring a SAN Environment for VMM.

VMM 2008 R2 provides the following enhancements:

SAN Migration into and out of Clustered Hosts

VMM 2008 R2 supports the use of SAN transfers to migrate virtual machines and highly available virtual machines into and out of a cluster. When you migrate a virtual machine into a cluster by using a SAN transfer, VMM checks all nodes in the cluster to ensure that each node can see the LUN and automatically creates a cluster disk resource for the LUN. Even though VMM automatically configures the cluster disk resource, it does not validate it. You must use the Validate a Configuration Wizard in Failover Cluster Management to validate the newly created cluster disk resource. To migrate a virtual machine out of a cluster, the virtual machine must be on a dedicated LUN that is not using CSV.

Expanded Support for iSCSI SANs

VMM 2008 supports SAN transfers of virtual machines that use initiator-based iSCSI target connections. This requires one iSCSI target for every LUN. VMM 2008 R2 adds support for LUN masking, which allows for multiple LUNs per iSCSI target and expands VMM support for iSCSI SAN vendors.

Support for Clusters

VMM does not provide any cluster management functionality. All host clustering configuration and cluster resource group management must be performed outside of VMM by using cluster management tools.

Adding Windows host clusters is supported only for hosts in a trusted domain.

VMware clusters and the creation and management of highly available virtual machines on VMware ESX Server host clusters.

Installing the VMM server on a cluster has not been tested and is not supported. To make the VMM server highly available, it is recommended that you install it on a highly available virtual machine.

VMM 2008 R2 provides the following enhancements:

Support for Clustered Shared Volume (CSV)

VMM 2008 R2 supports the Windows Server 2008 R2 clustered shared volume (CSV) feature. CSV enables all hosts on a Windows Server 2008 R2 failover cluster to access at the same time virtual machine files on a single shared logical unit number (LUN). Because all nodes on the cluster can access a single shared LUN, virtual machines have complete transparency about which nodes actually own a LUN. This enables live migration of virtual machines within the cluster because all nodes in the cluster can access any LUN.

Support for Veritas Storage Foundation for Windows

VMM 2008 supports creating highly available virtual machines only on a Physical Disk resource type in a failover cluster. VMM 2008 R2 extends this support to any storage class resource, such as Veritas Storage Foundation 5.1 for Windows (SFW). SFW is an online storage management solution for creating virtual storage devices from physical disks and arrays. Volumes created as part of a cluster resource group by using SFW are detected by VMM 2008 R2 and can be selected during virtual machine placement or migration. An SFW volume is limited to one virtual machine.

Support for Live Migration on Windows Server 2008 R2 Clustered Hosts

VMM 2008 R2 supports live migration between Windows Server 2008 R2 clustered hosts. With live migration, you can migrate a virtual machine from one node of a Windows Server 2008 R2 failover cluster to another node in the same cluster without any downtime. Because the virtual machine does not experience any downtime, the move is completely transparent to the users who are connected to the virtual machine.

Nota

VMM 2008 R2 supports the use of a highly available root management server (RMS) for Microsoft System Center Operations Manager 2007 with Service Pack 1 (SP1) or System Center Operations Manager 2007 R2 for PRO. Use of a highly available Operations Manager RMS is not a supported configuration in VMM 2008. For more information about integrating Operations Manager with VMM, see Configuring Operations Manager Integration with VMM (http://go.microsoft.com/fwlink/?LinkID=120283).

Support for a Disjointed Namespace

VMM supports adding and managing hosts that are in a disjointed namespace, which occurs when one or more computers have a primary Domain Name System (DNS) suffix does not match the DNS name of the Active Directory Domain Services (AD DS) domain of which the computers are members. For example, a member computer that uses a primary DNS suffix of corp.fabrikam.com in an AD domain named na.corp.fabrikam.com is using a disjointed namespace. For more information about a disjointed namespace, see Naming conventions in Active Directory for computers, domains, sites, and OUs (http://go.microsoft.com/fwlink/?LinkId=123886).

To use VMM in a disjointed namespace, you need to do the following:

To add hosts to VMM that are in a disjointed namespace, ensure that the DNS name of the computer is a registered host Service Principal Name (SPN) in Active Directory.

Support for Perimeter Networks

You can add and manage hosts on a perimeter network, but you must install the VMM agent locally on the hosts and then add them in the VMM Administrator Console. For more information about adding a host on a perimeter network, see Installing a VMM Agent Locally on a Host.

VMM does not support adding a clustered host that is on a perimeter network.

After you deploy virtual machines on a host that is on a perimeter network, you cannot migrate those virtual machines to a host on the internal network or to another host on the perimeter network.

Support for Distributed Resources

For geographically disperse organizations, VMM supports the use of distributed VMM library servers that are managed by a centralized VMM server. For example, if you have branch offices in multiple locations, users in those locations can build virtual machines by using resources from a local library server instead of copying multi-gigabyte files from a centralized library server over a wide area network (WAN). Having distributed VMM libraries can also help ensure the availability of files during WAN outages or server failures.

Nota

VMM does not provide a method for replicating physical files in the VMM library or metadata for objects that are stored in the VMM database. Physical files must be replicated outside of VMM and metadata must be transferred by using scripts or other means. VMM does not support DFS Namespaces (DFSN), formerly known as Distributed File System (DFS), or DFS Replication (DFSR).

Support for Windows PowerShell 2.0

VMM 2008 R2 adds support for Windows PowerShell 2.0 in addition to continuing support for Windows PowerShell 1.0. Windows PowerShell 2.0 has new cmdlets, parameters, and variables, and also provides many new features, including the following:

Remote management: You can run commands on one computer or on hundreds of computers by using a single command. You can establish an interactive session with a single computer, or you can establish a session that can receive remote commands from multiple computers.

Background jobs: By using Windows PowerShell background jobs, you can run commands asynchronously and "in the background" so that you can continue to work in your session. You can run background jobs on a local or remote computer, and you can store the results locally or remotely.

Debugger: You can use the Windows PowerShell debugger to help you debug functions and scripts. You can set and remove breakpoints, step through code, check the values of variables, and display a call-stack trace.

Quick Storage Migration

In VMM 2008 R2, for a Windows Server 2008 R2 host or a Storage VMotion-capable host, you can migrate a running virtual machine’s files to a different storage location on the same host with minimal or no service outage. If you migrate a virtual machine to a host that is running Windows Server 2008 R2 and you use a network transfer, VMM 2008 R2 now gives you the option to specify separate storage locations for each virtual hard disk (.vhd) file for the virtual machine.

Maintenance Mode for Hosts

In VMM 2008 R2, you can start maintenance mode for a Windows-based host anytime you have to perform maintenance tasks on the host, such as applying updates or replacing a physical component.

When you start maintenance mode on a host in a Windows Server 2008 R2 cluster with highly available virtual machines, you can do one of the following:

If the option is available, use live migration to evacuate all virtual machines to other hosts on the same cluster. If the migration fails for any virtual machine on the host, maintenance mode is not started on that host and VMM does not migrate back the virtual machines that have already migrated.

Place all virtual machines on the host into a saved state.

When you start maintenance mode on a stand-alone Windows-based host, on a host in a Windows Server 2008 cluster, or on a Windows Server 2008 R2 host that has any non-highly available virtual machines, VMM automatically places all virtual machines into a saved state.

Importante

When VMM places virtual machines into a saved state, any users of the virtual machines will experience a loss of service.

When you start maintenance mode on any host, VMM automatically does the following:

Blocks virtual machine creation operations on the host.

Excludes the host from the host ratings during placement.

Displays a host status of In Maintenance Mode in Host view of the VMM Administrator Console.

When you stop maintenance mode on a host, VMM allows virtual machine creation operations on the host, includes the host in the host ratings during placement, and displays a host status of OK in Host view of the VMM Administrator Console. However, VMM does not automatically do a live migration to move highly available virtual machines back onto the host in a Windows Server 2008 R2 cluster, and it does not restart any of the virtual machines on the host.

To start or stop maintenance mode, in Host view of the VMM Administrator Console, right-click a host, and then click the appropriate command.

Support for VMware Port Groups for Virtual Switches

VMM uses the network location and tag specified for the virtual network adapter in the hardware configuration to determine the network availability of a virtual machine on a host. In VMM 2008 R2, if you are deploying the virtual machine to a VMware ESX Server host, you can select from the VMware port groups that are available for virtual switches.

Support for VMware vNetwork Distributed Switches

VMM does not support VMware vNetwork Distributed Switches. Customers that want to manage their VMware environments with VMM should only use Standard Switches (formerly called vSwitches).

Support for Virtual Machine Permissions Assigned in Hyper-V

In VMM 2008 R2, VMM preserves changes that you make to role definitions or role memberships in the root scope of the Hyper-V authorization store. All changes to any other scope are overwritten every half hour by the VMM user role refresher. This differs from user role processing in VMM 2008. In VMM 2008, VMM determines access to virtual machines, hosts, and resources based only on the rights and permissions associated with VMM user roles. VMM 2008 does not make any changes to Hyper-V role definitions and role memberships. It just ignores the Hyper-V authorization store while the hosts and virtual machines are under its management.